Simon Stark returns to Whitechapel in east London as a Detective Inspector in Homicide. But Simon fears fieldwork and interacting with a team, because he has a few ... issues. He is severely OCD and voices in his head keep him pinned down to the Rules by which he must live his life. In his experience, people dislike him, and the feeling is mutual. Simon expects resentment, especially from Detective Sergeant Ralph Golding, who's been leading the team since the death of their previous inspector. But to his surprise, the team warms up quickly to him. Now Simon has to deal with the growing attraction between himself and Ralph while the Rules forbid such unprofessional behaviour. And when the demons living under Whitechapel begin to manifest, Simon has to face bigger dangers than just the voices in his head.